(1) Technical Field of the Invention
This invention relates to a photo printer for projecting an image of an original picture onto a photosensitive material through a lens so as to expose the photosensitive material to the thus-reproduced optical image, and more specifically to a photo printer for feeding, in proportion to a magnification ratio, a photosensitive material loaded in a rolled form within a magazine provided at a fixed position onto a focusing frame movable in the direction of an optical axis, setting it on the focusing frame, exposing it and then receiving the exposed photosensitive material within a receiving magazine.
(2) Description of the Prior Art
Automated photo printers are now widely used in printing work, in which color sensitive paper sheets are exposed to optical images of negative color original films so as to reproduce color pictures. In each of such photo printers, a web-like color sensitive paper is stored in a rolled form within a magazine. The color sensitive paper is fed out to a focusing plane as needed, so that the color sensitive paper is exposed to an image of an original, followed by feeding-out of the thus-exposed paper to a receiving side. Two types of photo printers are known depending on the manner of the feeding-out. In one type of photo printers, an exposed paper web is wound up into a roll while maintaining its web-like form (roll-to-roll mode). In the other type of photo printers, an exposed paper web is cut into sheets, followed by their storage in the sheet-like form within a magazine (roll-to-sheet mode).
Either one of these modes is chosen depending on the production scale of a work shop where a photo printer is used, the type of processing of exposed paper, etc. In a large-scale shop in which a roll of color sensitive paper is used in a continuous operation, a high level of work efficiency can be achieved when the roll-to-roll mode is adopted to permit feeding of exposed paper in a rolled form to a processor. On the other hand, the use of the roll-to-sheet mode is reasonable for a small-scale shop where color sensitive paper is not consumed so much as the large-scale shop.
However, the demand for color printing is not always high even in a large-scale shop. It is thus necessary to use the "roll-to-sheet mode" from time to time in the large-scale shop, although the "roll-to-roll mode" is usually employed there. Since there has not been available any color photo printer which enables to practice both types of the modes, use of both modes results automatically in the installation of two types of photo printers, one of the "roll-to-roll mode" and the other of the "roll-to-sheet mode", in other words, double investments. This is certainly uneconomical.
There have also been known photo printers, each of which allows to adjust the magnification ratio upon projection of an image so as to obtain a reproduced picture of a desired size. To achieve this function, it is indispensable to adopt such a design that desired two of an original film, a lens and a focusing plane are movable in the direction of the optical axis. Since it is rather common to load different original films one after another in general printing work, it is advantageous to maintain the loading position of such original films at the same position for the convenience of the operation. It is hence preferred to move the lens and focusing plane. If the focusing plane with a color sensitive paper held thereon is moved and the magazine with a roll of color sensitive paper stored therein is fixed, it is difficult to transport the web of color sensitive paper (hereinafter called "paper web" or "web" for the sake of brevity) from the magazine to the focusing plane. This requires to move the magazine and focusing plane as unitary members, leading to an disadvantage that the moving part is increased in both bulk and weight.